The measure will now go to the Illinois House, where a contentious fight is expected before the bill can reach Gov. Pat Quinn’s desk. Quinn is expected to sign the bill, and issued a statement on Thursday praising the Democratic-led Senate vote.

“Today, we are one step closer to marriage equality in Illinois,” Quinn said in a statement. “Couples across Illinois have even more reason today to celebrate their love for each other, thanks to the hard work of committed advocates and lawmakers.”

Praise also came from Chicago mayor and former chief of staff to President Obama, Rahm Emanuel, who called on the Illinois House to pass the bill.

“When two people love each other, no government entity should stand in the way of letting them express that love,” said Emanuel. “It is time that our laws reflect our values and I am so proud that on this Valentine’s Day, the Illinois Senate has voted to approve gay marriage.”

If passed, the measure would officially change state law from an act between a man and a woman to two people. Illinois residents in civil unions would be able to convert them to marriages with a year of the law going into effect.

It is not clear yet when the Illinois House will take up the measure.

The president’s home state would become the 10th state to legalize same-sex matrimony, and the first in the midwest to do so through legislation. Obama announced last year he supports gay marriage.